1. Field
Apparatuses consistent with exemplary embodiments relate to semiconductor memory devices, and more particularly, to high density semiconductor memory devices.
2. Description of the Related Art
Higher integration of semiconductor memory devices is required to satisfy consumer demands for superior performance and inexpensive prices. In the case of semiconductor memory devices, since their integration is an important factor in determining product prices, increased integration density is required.
For semiconductor memory devices, a metal-oxide-semiconductor (MOS) transistor with a horizontal channel is used as a switching device, and in this case, a unit cell has a cell size ranging from 6F2 to 8F2 (where F is the minimum feature size). Using a diode as the switching device may allow reducing the cell size to about 4F2. In this case, however, due to a rectifying property of the diode, it may suffer from a technical difficulty in realizing a bi-directional current characteristic.